Business Analyst: What is SQL GROUP BY and HAVING?

GROUP BY — aggregate rows by column. HAVING — filter groups.

Example:

1-- Total sales by country
2SELECT country, SUM(amount) as total_sales
3FROM orders
4GROUP BY country;
5
6-- Countries with sales over $10,000
7SELECT country, SUM(amount) as total_sales
8FROM orders
9GROUP BY country
10HAVING SUM(amount) > 10000;

Aggregate functions:

• COUNT() — number of rows.
• SUM() — total.
• AVG() — average.
• MIN() — minimum.
• MAX() — maximum.

Difference:

• WHERE — filter rows before grouping.
• HAVING — filter groups after grouping.